This invention relates to intraocular lenses (IOLs) and, more particularly, to IOLs which inhibit migration or growth of cells from the eye onto the IOL and reduce glare in the eye.
An intraocular lens is commonly used to replace the natural lens of a human eye when warranted by medical conditions. It is common practice to implant an IOL in a region of the eye known as the capsular bag or posterior capsule.
One potential concern with certain IOLs following implantation is that cells from the eye, particularly epithelial cells from the capsular bag, tend to grow in front of and/or in back of the optic of the IOL. This tends to block the optic of the IOL and to impair vision.
A common treatment for this condition is to use a laser to destroy the cells and a central region of the capsular bag. Although this treatment is effective, the laser is expensive and is not available throughout the world. There is also cost associated with the laser treatment as well as some patient inconvenience and risk of complications. Finally, the laser treatment may affect the performance of some IOLs.
Another potential concern after certain IOLs are implanted has to do with glare caused by light reflecting off of the IOLs, in particular, the edges of IOLs. Such glare can be an annoyance to the patient and may even lead to removal and replacement of the IOL.
It would be advantageous to provide IOLs which inhibit growth of cells from the eye onto the IOLs and/or which reduce glare caused by the IOLs in the eye.
New IOLs have been discovered. Such IOLs are effective to inhibit cell growth, in particular epithelial cell growth, from the eye onto the optic of the IOLs. The IOLs are structured so as to reduce glare, in particular edge glare, in the eye resulting from the presence of the IOL. The present IOLs are straightforward in design and construction, are easily manufactured, can be implanted, or inserted in the eye using conventional techniques, and are effective and produce substantial benefits in use in the eye.
In one broad aspect of the present invention, the present IOLs are implantable in the eye and comprise an optic having a central optical axis, an anterior face, an opposing posterior face and a peripheral edge or edge surface between the faces. The optic is adapted for placement in the capsular bag of the eye and for directing light toward the retina of the eye. In a very useful embodiment, the IOLs further comprise at least one fixation member, preferably two fixation members, and more preferably two elongated fixation members, coupled to the optic for use in fixing the IOLs in the eye.
In a preferred aspect, the present invention provides a reduced-glare intraocular lens implantable in the eye and including an optic adapted for placement in the capsular bag of the eye for directing light toward the retina of the eye. The optic has a central optical axis, an anterior face, an opposing posterior face, and a peripheral edge. The peripheral edge has a least one surface with a linear cross-sectional configuration that is oriented other than parallel to the central optical axis. Further, the peripheral edge and the anterior face, and/or the peripheral edge and the posterior face, intersect to form at least one peripheral edge corner located at a discontinuity between the peripheral edge and the intersecting anterior or posterior face. The peripheral edge may also include a rounded transition surface on its anterior side, wherein the peripheral edge corner is provided only between the peripheral edge and intersecting posterior face. The peripheral edge may also include two linear surfaces angled with respect to one another, wherein the other linear surface may be oriented parallel to the optical axis.
In another aspect of present invention, a reduced-glare intraocular lens implantable in an eye comprises an optic adapted for placement in the capsular bag of the eye and for directing light toward the retina of the eye. The optic has a central optical axis, an anterior face, and a posterior face. An outer edge of the optic is defined by a peripheral edge that includes, in cross-section, a linear surface that is non-parallel with respect to the optical axis and a posterior corner defining the posterior limit of the peripheral edge. Advantageously, cell growth from the eye in front of or in back of the optic is more inhibited relative to a substantially identical intraocular lens without the posterior corner, and reduced glare is obtained in the eye relative to a substantially identical intraocular lens having a peripheral linear surface that is parallel to the central optical axis. The optic may also include a convex surface on the peripheral edge defining a transition surface between the anterior face and the linear surface. A second linear surface that is parallel with respect to the optical axis may also be provided. In addition, the optic may include first and second linear surfaces, wherein the first linear surface is anteriorly-facing and second linear surface is parallel with respect to the optical axis.
In still a further embodiment of the present invention, an intraocular lens implantable in an eye includes an optic adapted for placement in the capsular bag of the eye and for directing light toward the retina of the eye. The optic includes a peripheral edge extending between an anterior face and a posterior face consisting only of a conical surface. The conical surface may be posteriorly-facing, wherein the conical surface is sufficiently angled with respect to the optical axis so as to increase transmission of light from the optic through the conical surface relative to a substantially identical intraocular lens with a peripheral edge consisting only of a surface parallel to the optical axis. Alternatively, a peripheral land extends between the anterior face and conical surface, wherein the conical surface is generally posteriorly-facing and wherein the conical surface and the peripheral land adjacent the conical surface define an acute included angle. In a still further form, the conical surface may be anteriorly-facing, wherein the conical surface is sufficiently angled with respect to the optical axis so as to decrease the probability of light internal to the optic contacting the conical surface relative to a substantially identical intraocular lens with a peripheral edge consisting only of a surface parallel to the optical axis.
Another aspect of present invention is an intraocular lens including an optic defining a central optical axis, an anterior face, and a posterior face. A peripheral edge extending between the anterior face and the posterior face includes, in cross-section, a linear edge surface terminating at its anterior side in an anterior edge corner. An anterior land adjacent the anterior edge corner, wherein the linear edge surface and the anterior land define an acute included angle so as to increase transmission of light from the optic through the conical surface relative to a substantially identical intraocular lens with a linear edge surface and anterior land that define an included angle of 90xc2x0 or more.
In a still further form, the present invention provides an intraocular lens having optic defining optical axis, an anterior face, and a posterior face. A peripheral edge stands between the anterior face and posterior face and includes, in cross-section, at least two linear edge surfaces that are not parallel to the optical axis. The two linear edge surfaces may be angled radially inwardly toward each other to meet an apex and together define a groove. Further, a plurality of such grooves may be provided by adjoining linear edge surfaces. A rounded transition surface extending between an anteriorly-facing edge surface and the anterior face of the optic may also be provided.
The peripheral edge of the present IOLs may have a curved surface, a flat surface that is either parallel to the optical axis or not, or a combination of flat and/or curved surfaces. For example, if a portion of the peripheral edge has a substantially continuous curved configuration, another portion, for example, the remaining portion, of the peripheral edge preferably has a linear configuration in the direction between the anterior and posterior faces of the optic which is not parallel to the optical axis.
The present IOLs preferably provide reduced glare in the eye relative to the glare obtained with a substantially identical IOL having a peripheral edge parallel (flat) to the central optical axis in the direction between the faces of the optic. One or more of at least part of the peripheral edge, a portion of the anterior face near the peripheral edge and a portion of the portion face near the peripheral edge may be at least partially opaque to the transmission of light, which opacity is effective in reducing glare. Such opacity can be achieved in any suitable manner, for example, by providing xe2x80x9cfrosting xe2x80x9d or physically or chemically roughening selected portions of the optic.
In addition, the intersection of the peripheral edge and at least one or both of the anterior face and the posterior face forms a peripheral corner or corner edge located at a discontinuity between the peripheral edge and the intersecting face. Such peripheral corner, which may be considered a sharp, abrupt or angled peripheral corner, is effective in inhibiting migration or growth of cells from the eye onto the IOL. Preferably, the present IOLs, with one or two such angled peripheral corners, provide that cell growth from the eye in front of or in back of the optic is more inhibited relative to a substantially identical IOL without the sharp, abrupt or angled peripheral corner or corners.
The peripheral edge and the intersecting face or faces intersect at an angle or angles, preferably in a range of about 45xc2x0 to about 135xc2x0, more preferably in a range of about 60xc2x0 to about 120xc2x0. In one embodiment, an obtuse angle (that is greater than 90xc2x0 and less than 180xc2x0) of intersection is provided. Such angles of intersection are very effective in facilitating the inhibition of cell migration or growth onto and/or over the anterior face and/or posterior face of the optic of the present IOL.
In one very useful embodiment, at least one of the anterior face and the posterior face has a peripheral region extending from the peripheral edge toward the central optical axis. The peripheral region or regions preferably are substantially planar, and may or may not be substantially perpendicular to the central optical axis. Preferably, only the anterior face has a peripheral region extending from the peripheral edge toward the central optical axis which is substantially planar, more preferably substantially perpendicular to the central optical axis. The peripheral region preferably has a radial dimension of at least about 0.1 mm, and more preferably no greater than about 2 mm.
The dimension of the optic parallel to the central optical axis between the anterior face and the posterior face preferably is smaller at or near the peripheral edge, for example, at the peripheral region or regions, than at the central optical axis.
Preferably, the peripheral edge and/or the peripheral region or regions circumscribe the central optical axis. The anterior face and the posterior face preferably are both generally circular in configuration, although other configurations, such as oval, elliptical and the like, may be employed. At least one of the anterior and posterior faces has an additional region, located radially inwardly of the peripheral region, which is other than substantially planar.
Each and every combination of two or more features described herein is included within the scope of the present invention provided that such features are not mutually inconsistent.